First of all having let the board go fast I now have renewed respect for kite board racers.

Damn things are fast s hell.

I was out on a FreeRace by north... and I'm guessing it's not the fastest this out there.

I'm 225LBS and was riding at the most 25mph wind with a rather old Naish Bolt 9m.

Even fully depowered it was like a rocket once unto speed. Just sheeting in a little would accelerate in leaps and bounds.
Going a little upwind and against the swell was like dirt biking with a Wide Ration gear box screaming through the whoops in the desert. Going over the swell at high speed made for 4 to 5 foot jumps... but 30 to 50 feet long. Sort of reminded me of windsurfing at high speeds a bit.

What was also interesting is that I did a long downwinder too and ended up at a beach with much lower wind. It would take working the kite a bit to get going, but once the board was planning it was like the wind came from nowhere. I was screaming along with almost no bar pressure.
Brilliant

Going straight downwind in the light wind was a bit of a slog, but on a broad reach it would take.

Anyway I've got the bug now and this is going to be fun on light flat days.

The fastest way downwind is "tacking" downwind on broad reaches. You need to get going really fast pointing a bit higher first. This make the apparent wind shift around in front of you. Then gradually head downwind as you pick up speed. You should still be pushing against the fins a bit.

So you're on a broad reach to the true wind angle, but close reach to th apparent wind angle.

Then play with heading up and down to keep ypur speed up and tension in the lines.